This invention relates to apparatuses and methods for providing controlled exercise and support.
Braces for jointed anatomical limb segments such as the leg and thigh or the arm and forearm are known. The braces have joints that permit motion of the limb segments, such as for example, motion of the leg with respect to the thigh about the knee, the thigh and trunk about the hip, the arm and trunk about the shoulder and the forearm and arm about the elbow. Such braces may include stops to limit motion.
In one class of exercise equipment, provision is made to attach the exercise equipment to a brace-like structure or to a brace-like fastening means that is part of the equipment. This type of brace-like equipment attaches to the limb segments to permit exercise of the braced part, such as for example, to permit or limit exercise of the leg and thigh about the knee or the arm and forearm about the elbow.
Prior art exercise techniques are conventionally classified as isometric, isotonic, and isokinetic. An additional fourth classification has become recently recognized and called individualized dynamic variable resistance. All of these techniques except isometric utilize motion of the limb for strengthening or treating an injured muscle and all of the techniques have corresponding exercise equipment associated with them.
One type of prior art isokinetic technique and corresponding exercise equipment is machine operated. The patient moves and either flexes a joint through predetermined range using motor control and resists movement by the patient with a force proportional to the speed of movement of the patient. This type of equipment has the disadvantage of being expensive, and under some circumstances, of not providing a controlled level of muscular exertion appropriate for the position of the parts being exercised since it is stationed on a fixed surface such as the floor.
Isotonic exercise equipment includes weights and a mechanism for applying the weights to the anatomical segment so that the patient exerts effort against the weights. This type of prior art exercise equipment has the disadvantages of: (1) continuously providing resistance of the same amount regardless of the position of the limb being exercised; (2) continuance of the force when the patient stops moving if the weight is elevated; and (3) being only uni-directional in a concentric (shortening muscle) sense.
A newer type of prior art exercise equipment and technique involving motion is individualized dynamic variable resistance. This equipment measures a limb's strength ability isokinetically to establish a motor performance curve. This curve is a relationship between degrees and the range of motion and resistance to that motion. During exercising, the resistance is provided over a distance corresponding to the range of motion as a fixed percentage of the maximum established by that curve. The curve is followed but at a preset level such as one-fourth of its maximum value.
In the equipment using, this technique, the curve is measured and recorded and then during exercise, a feedback mechanism senses the position and obtains a signal corresponding to the proportion of resistance corresponding to that position. This signal controls the amount of force applied through a magnetic particle brake attached to the limb. Equipment utilizing this technique is disclosed in U.S. Pat. No. 4,869,497 granted Sep. 26, 1989.
This technique has several disadvantages under certain circumstances, such as: (1) continuing a resistive force after motion has stopped; (2) being adaptable only to open kinetic chain exercise; (3) being dependent to some extent on controlled speed of movement to provide the appropriate resistance; (4) the equipment is fixed to a particular locality when in use, as well as to the patient; (5) the equipment is bulky and cannot be easily moved from place to place; and (6) the user may inadvertantly use other muscles to change the exercise pattern because the muscle cannot be easily isolated with equipment mounted to equipment on which the patient sits or stands or to the ground since the patient may be able to exert leverage with another part of the body. This technique also has the disadvantage of being too inflexible and not accomodating resistance programs developed for specific purposes; such as to strengthen fast twitch or slow twitch muscles individually or for a program prescribed to accomodate a particular limb position for development of particular muscles in a manner deviating from the motor performance curve.